JEEP GRAND CHEROKEE 2008 WK / 3.G Owners Manual

Transmission Limp Home Mode
Transmission function is monitored for abnormal condi-
tions. If a condition is detected that could result in
transmission damage, the transmission limp home mode
will be engaged. In this mode, the transmission will
remain in the current gear (3.7L engine) or in direct gear
(4.7L and 5.7L engines) until the vehicle is brought to a
stop.
To reset the transmission, use the following procedure:
1. Stop the vehicle.
2. Move the shift lever to the P (Park) position.
3. Turn off the engine, be sure to turn the key to the
LOCK position.
4. Wait approximately 10 seconds, then restart the en-
gine.
5. Move the shift lever to the desired gear range.If the problem is no longer detected, the transmission will
return to normal operation. If the problem persists, P
(Park), R (Reverse), and N (Neutral) will continue to
operate. Only 2nd gear (3.7L engine) or 3rd gear (4.7L
and 5.7L engines) will be available in the D (Drive)
position. Have the transmission checked at your autho-
rized dealer as soon as possible.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at a calibrated speed at light throttle. It engages at
higher speeds under heavier acceleration. This may re-
sult in a slightly different feeling or response during
normal operation in high gear. When the vehicle speed
drops below a calibrated speed, or during acceleration,
the clutch automatically and smoothly disengages. The
feature is operational in Overdrive and in Drive.
STARTING AND OPERATING 291
5

NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmission
is not shifting into Overdrive when cold. This is normal.
Manually shifting (using the ERS shift control) between 4
(direct gear) and 5/D (Overdrive gear) positions will
demonstrate that the transmission is able to shift into and
out of Overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission into gear may seem sluggish. This is due to
the fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque converter
will refill within five seconds of shifting from Park into
any other gear position.Rocking the Vehicle
If the vehicle becomes stuck in snow, sand, or mud, it can
often be moved by a rocking motion. Move the gear
selector rhythmically between D (Drive) and R (Reverse),
while applying slight pressure to the accelerator.
NOTE:The Electronic Stability Program (ESP) and
Traction Control (if equipped) should be turned OFF
before attempting to rock the vehicle. Refer to ªElectronic
Brake Control Systemº in Section 3 of this manual.
The least amount of accelerator pedal pressure to main-
tain the rocking motion without spinning the wheels or
racing the engine is most effective. Racing the engine or
spinning the wheels, due to the frustration of not freeing
the vehicle, may lead to transmission overheating and
failure. Allow the engine to idle with the transmission
selector in N (Neutral) for at least one minute after every
292 STARTING AND OPERATING

five rocking-motion cycles. This will minimize overheat-
ing and reduce the risk of transmission failure during
prolonged efforts to free a stuck vehicle.
CAUTION!
When ªrockingº a stuck vehicle by moving between
ªFirstº and R (Reverse), do not spin the wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
FOUR-WHEEL DRIVE OPERATION
Quadra-Trac ITOperating
Instructions/Precautions Ð If Equipped
The Quadra-Trac Itis a single speed (HI range only)
transfer case which provides convenient full-time
4±wheel drive. No driver interaction is required. This
transfer case divides engine torque almost evenly with 48percent of engine torque to the front axle and 52 percent
of engine torque to the rear axle. The Brake Traction
Control System (BTC), which combines standard ABS
and Traction Control, provides resistance to any wheel
that is slipping to allow additional torque transfer to
wheels with traction.
NOTE:The Quadra-Trac Itsystem is not appropriate
for conditions where LOW range is recommended. Refer
to ªOff-Road Driving Tipsº in this section.
Quadra-Trac IITOperating
Instructions/Precautions Ð If Equipped
The Quadra-Trac IIttransfer case is fully automatic in the
normal driving 4 HI mode. The Quadra-Trac IIttransfer
case provides three mode positions Ð four wheel drive
high range, neutral, and four wheel drive low range.
This transfer case is fully automatic in the 4 HI mode.
This transfer case divides engine torque almost evenly
with 48 percent of engine torque to the front axle and 52
STARTING AND OPERATING 293
5

percent of engine torque to the rear axle. When speed
differences are increased between the front and rear drive
shafts, the transfer case can transmit up to 100 percent of
available engine torque to the front or rear drive shafts.
When additional traction is required, the 4 LOW position
can be used to lock the front and rear driveshafts together
and force the front and rear wheels to rotate at the same
speed. The 4 LOW position is intended for loose, slippery
road surfaces only. Driving in the 4 LOW position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed
is approximately three times that of the 4 HI position at a
given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).Proper operation of four wheel drive vehicles depends on
tires of equal size, type, and circumference on each
wheel. Any difference will adversely affect shifting and
cause damage to the transfer case.
Because four wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
294 STARTING AND OPERATING

WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in the N
(Neutral) position without first fully engaging the
parking brake. The transfer case N (Neutral) position
disengages both the front and rear driveshafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle.
Shift Positions
For additional information on the appropriate use of each
transfer case mode position, see the information below:
4HI
Four Wheel Drive High Range Ð All roads surfaces such
as ice, snow, gravel, sand, and dry hard pavement.
N (Neutral)
Neutral Ð Disengages both the front and rear driveshafts
from the powertrain. To be used for flat towing behind
another vehicle. Refer to ªRecreational Towingº in Sec-
tion 5 of this manual.
4 LOW
Four Wheel Drive Low Range Ð Low speed 4 wheel
drive. Locks the front and rear driveshafts together.
Forces the front and rear wheels to rotate at the same
speed. Additional traction and maximum pulling power
for loose, slippery road surfaces only. Do not exceed 25
mph (40 km/h).
STARTING AND OPERATING 295
5

Shifting Procedures
4HIto4LOW
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. ªThe 4WD
LOW Indicator Lampº in the instrument cluster will
begin to flash and remain on solid when the shift is
complete. Release the T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a ªCHECK SHIFT PROCEDURESº message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to ªElectronic Vehicle Information Center
(EVIC)º in Section 4 of this manual.
Shifter T-Handle
296 STARTING AND OPERATING

4 LOW to 4 HI
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. The ª4WD
LOW Indicator Lampº in the instrument cluster will flash
and go out when the shift is complete. Release the
T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a ªCHECK SHIFT PROCEDURESº message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to ªElectronic Vehicle Information Center
(EVIC)º in Section 4 of this manual.NOTE:Shifting into or out of 4WD LOW is possible
with the vehicle completely stopped, however difficulty
may occur due to the mating clutch teeth not being
properly aligned. Several attempts may be required for
clutch teeth alignment and shift completion to occur. The
preferred method is with the vehicle rolling 0 to 3 mph (0
to 5 km/h). If the vehicle is moving faster than 3 mph (5
km/h), the transfer case will not allow the shift.
Neutral (N) Shift Procedure
1. Key ON, engine off.
2. Vehicle stopped, with foot on brake.
3. Place transmission in N (Neutral).
STARTING AND OPERATING 297
5

4. Hold down N (Neutral) ªpinº switch (with a pen, etc.)
for 4 seconds until the LED lamp by the switch starts to
blink indicating shift in progress. Lamp will stop blinking
(stay on solid) when Neutral shift is complete. A ª4WD
SYSTEM IN NEUTRALº message will display on the
EVIC (Electronic Vehicle Information Center). Refer to
ªElectronic Vehicle Information Center (EVIC)º in Sec-
tion 4 of this manual.
5. Repeat Steps 1± 4 to shift out of Neutral.
NOTE:If shift conditions/interlocks are not met, a
ªCHECK SHIFT PROCEDURESº message will flash from
the EVIC (Electronic Vehicle Information Center). Refer
to ªElectronic Vehicle Information Center (EVIC)º in
Section 4 of this manual.
Neutral Switch
298 STARTING AND OPERATING

Quadra-Drive IITSystem Ð If Equipped
The optional Quadra-Drive IItSystem features three
torque transfer couplings. The couplings include ELSD
(Electronic Limited Slip Differential) front and rear axles
and Quadra-Trac IIttransfer case. The optional ELSD
axles are fully automatic and require no driver input to
operate. Under normal driving conditions the units func-
tion as standard axles balancing torque evenly between
left and right wheels. With a traction difference between
left and right wheels the coupling will sense a speed
difference. As one wheel begins to spin faster than the
other, torque will automatically transfer from the wheel
that has less traction to the wheel that has traction. While
the transfer case and axle couplings differ in design, their
operation is similar. Follow the Quadra-Trac IIttransfer
case shifting information, preceding this section, for
shifting this system.
ON-ROAD DRIVING TIPS
Utility vehicles have higher ground clearance and a
narrower track to make them capable of performing in a
wide variety of off-road applications. Specific design
characteristics give them a higher center of gravity than
ordinary cars.
An advantage of the higher ground clearance is a better
view of the road, allowing you to anticipate problems.
They are not designed for cornering at the same speeds as
conventional 2-wheel drive vehicles any more than low-
slung sports cars are designed to perform satisfactorily in
off-road conditions. If at all possible, avoid sharp turns or
abrupt maneuvers. As with other vehicles of this type,
failure to operate this vehicle correctly may result in loss
of control or vehicle rollover.
STARTING AND OPERATING 299
5

OFF-ROAD DRIVING TIPS
NOTE:Prior to off-road driving, remove the front air
dam to prevent damage. The front air dam is attached to
the lower front fascia with quarter turn fasteners, and can
be removed by hand.
When To Use 4WD LOW Range Ð If Equipped
When off-road driving, shift to 4WD LOW for additional
traction. This range should be limited to extreme situa-
tions such as deep snow, mud, or sand where additional
low speed pulling power is needed. Vehicle speeds in
excess of 25 mph (40 km/h) should be avoided when in
4WD LOW range.
Driving Through Water
Although your vehicle is capable of driving through
water, there are a number of precautions that must be
considered before entering the water:
CAUTION!
When driving through water, do not exceed 5 mph (8
km/h). Always check water depth before entering as
a precaution, and check all fluids afterward. Driving
through water may cause damage that may not be
covered by the new vehicle limited warranty.
Driving through water more than a few inches deep will
require extra caution to ensure safety and prevent dam-
age to your vehicle. If you must drive through water, try
to determine the depth and the bottom condition (and
location of any obstacles) prior to entering. Proceed with
caution and maintain a steady controlled speed less than
5 mph (8 km/h) in deep water to minimize wave effects.
Flowing Water
If the water is swift flowing and rising (as in storm
run-off) avoid crossing until the water level recedes
300 STARTING AND OPERATING